The Truth About A Multiscale Guitar's Fret Wire Radius

Is the radius of a multiscale guitar's fret wire the same as the fretboard? It's complicated. This video will attempt to explain. If you would like to help support my channel and get something cool in return, please consider the following:

[davidjohnston]

A fan fret is a small segment of a diagonal section through a cylinder. A non perpendicular section of a cylinder is an ellipse. The ellipse has foci with distance from the center as d = r tan(theta) = r*sqrt(( sec^2 theta )-1). Theta is the angle from the centerline. So you don't have a "radius". It's an ellipse and the curvature changes along the length of the fret.

[MohammadmahdiKarimi-hqiq]

Hi. The formula is R = r/cos(theta) where theta is 0 for vertical frets.
Although someone pointed out that the fret is not part of a perfect circle, a local radius can still be defined and will probably work very well since the frets are so short compared to the radius. You can measure the angle and check it out for that first fret!

[MarkRawling]

Ha, nice vid! There are a couple of practical points here: 1. you might want to choose a different fret pressing caul (probably doesn''t really matter) and 2.stainless steel frets - they are so hard to bend while pressing in that for mutliscale it might be nice to have wire bent in a sort of smooth spiral and use the part that closest matches the fret you're inserting. YMMV!

[restojon]

Started watching for the guitar knowledge. Left with nostalgia for watching Cheers 🍻.

Time to watch some re-runs. Thanks for the reminder

🎶 where everybody kno-ows yourrr na-aame 🎶

[DavidRavenMoon]

On any guitar the wire is on top of the fretboard. So it’s slightly larger radius.

But it doesn’t matter. Unless you are using stainless steel wire you should over bend the fret wire.

Also I had a long conversation with Ken Parker back in the 90s… he pointed out that it doesn’t matter. In regards to keeping a constant radius he said “it doesn’t matter. Just take a hand plane and get it as close as possible.” You can see photos of basses with purposely twisted necks. But they still play fine because as far as each string is concerned the path to the nut is straight.

[tarsiousmunalembohol]

You already uploaded how you leveled that neck?

[sgt.grinch]

45 minutes late. Just got home from my doctor’s appointment. Thanks for the education.

[goder]

Nice explanation, thank you!
What about fret wire radius of non-slanted, but with compound radius fretboard? If I understand it right, every fret will have it's own radius? Do you need to bend them right before installation?